Process of distillation and apparatus therefor.



G. L. PRICHARD,

PROCSS 0F DISTILLATION AND APPARATUS THEREFOR. APPLICATION FILED JUNE28. |916.

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G. L. PRIC'HARD.

' APPLICATION FILED .IUNE 28, I9I6.

PocE-s's of msmLAnoN AND APPARATUS THEREFOR.

. Port Arthur, y I State of Texas, have invented certain newprogressively raised in RTI-rua,` TEXAS,

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ASSIGNOR TO GULF REFINING COM- PANY, OF PITTSBURGH, PENNSYLVANIA, ACGRlPORATION 0F TEXAS. n

PROCESS 0F DSTILLATIN ND l' Aros rnnnnroa.

To all wko/1n t may concern Be it known that l, GEORGE L. PRICHARD, acitizen of the United States, residing at in the county of Jefferson andand useful Improvements in AProcesses of Distillation and ApparatusTherefor, of which the following is a specification.

This invention relates to processes of distillation and apparatustherefor; and it comprises a method of obtaining uniform cuts orfractionstroleum naphtha and similar distillates wherein such adistillate is redistilled with the aid of .steam heat in a plurality ofsuccessive stills operating in series as regards the material to bedistilled, the liquid being submitted to a prolonged and methodicalevaporative treatment in each such still and the, vapors from each suchstill being thoroughly dephlegmated with the aid of inflowing liquid,and the residual oil discharged freed from the oils of the severaldistillates, and it also comprises an assemblage of apparatus elementsuseful in the performance of such process and comprising a plurality ofsteam heated stills arranged for successive treatment of naphtha or thelike, each such still being arranged to distil liquid passing in transittherethrough 1n a comparatively long path and each being provided withmeans for thorough dephlegmatory exchange between the vapors therefromand the liquid fed thereto; all as more fully hereinafter set forth andas claimed.

In the manufacture of distilled commerI cial products from petroleum, itis customary to take od and condense a product called crude naphtha.This crude naphtha is afterward redistilled with the aid of steam forthe preparation of various naphtha products or naphthas of dilferentgravities; which, for lack of better names, may, beginning with thelightest, be called gasolene, naphtha and benzin. In the still remains acomparatively high boiling residual oil which is the equivalent-of theordinary kerosene distillate. Tn this distillation heat is usuallyfurnished by blowing free steam into the still through perforated pipesarranged near the bottom of the still. Sometimes the heat of steam coilsis resorted to fpr distillation (close steam).I The distilla' Wh tlon isordinarily in a slngle still which is temperature with Specication ofLetters Patent.

Application led .Tune 28, 1916.

and products from pe-.

Y fractions or cuts Patented Apr.. 30, ilml. serial no. 106,401.

separate collection of the condensates or cuts coming over at desiredtemperature intervals. This operation is of course intermittent, and itis diiiicult to secure as uniform products in a single operation as isdesirable. Tf the operation be so conducted as to give properlyseparated distillates the quality of the residual oil (kerosene) suffersand on the other hand if the operation be so conducted as to give asatisfactory residual oil the quality of the distillates is not so good.And in any event the several are not well separated from each other.

ln the present invention I have devised a method and provided anapparatus adapted for making such a separation as that above indicated,obtaining better distilled products in the sense of materials havingnarrower range of boiling points and being to that extent much moredefinite than those usually obtained in `redistilling the crude naphthawhile also giving a goodquality residual oil (kerosene). For thispurpose, instead of using a single still and collecting the variousfractions or cuts from it successively, I distil the liquid, so tospeak, in transit, using a plurality of stills, each vof which isadapted to furnish a single cut and passing the flowing liquid whichsupplies this stillin a countercurrent against the vapors coming fromsuch still. The liquid flows through the plurality of stills insuccession, the liquid from the first such still being supplied incountercurrent against the vapors coming from the second such still andso on. And T provide the interior of each such still with baffles orsimilar devices adapted to cause the liquid introduced at one end of thestill to travel progressively toward the other end of the still. Theundistilled residual oil finally discharged is freed of all oilsvolatile at the temperatures employed in distillation.

ile T may use any type of steam heated still and arrange these stills inany desired manner, yet I find it better to use a certain particularconstruction and relation. of the several stills and their settings. .lfind that it is desirable to superimpose the several stills in verticalarrangement as this gives convenience in operation and connections. en'so superimposed, the stills may be supported in any of the ordinarytypes of setting, but l ind it better to use a special `to the thirdstill.

steel skeleton frame carrying supporting cradles, etc. and a specialtype of heat insulation for each still (see the application of HerbertHenderson Serial No. 84180, filed March 14, 1916). In so arranging thestills, a steel skeleton frame is employed and the several stills aresupported therefrom on cradles while each still is provided with heatinsulation in a special manner; being covered with an outer layer ofheat insulating material at its top and an inner layer of heatinsulation at the bottom. The upper layer of heat insulation may besupported on suitable angle irons projecting from the sides of the stillbodies which may be, as usual, horizontal steel cylinders. Ar-

.ranging the insulation in this manner renders detection of leakage,repairs, etc. easily practicable.

I shall hereinafter describe my process and organization of apparatuselements as applied to the manufacture of three differ'- ent cuts from apetroleum product of the nature of the crude naphtha described, it beingunderstood -that I may use two such stills or more than three withoutdeparting from the principles of my invention. In such an organization,I mount the three stills-one above the other with the still 0perating atthe lowest temperature at the top. Each of the stills communicates withits own tower or dephlegmatory column which may be provided withinternal baffles or shelves. For structural convenience, I may mountthese three columns in the form of a single column divided by suitablepartitions at proper points. The incoming liquid is supplied to the topof the sub-tower connected with. the rst or topmost still and passesdownward through this subtower against the vapors passing upwardtherethrough from the still until the liquid reaches the bottom of thesub-tower whence it is supplied into the still. The residual liquidcoming from this first still is similarly supplied to `the sub-tower ofthe next succeeding still; and from the second still the residual liquidsimilarly goes High test residual oil thoroughly freed of mattersvolatile at the temperatures employed, is withdrawn from the last stillin the series and cooled in any suitable manner. Although specialfilmevaporating stills may be employed, I find it desirable to usestills of the Ordinar cylindrical shape but each provided with aplurality of baiiie plates to give a circuitous liquid iow therethrough.Three baiies may be used in each still. The vertical arrangement of thestills with the fresh liquid supplied at the top allows feed through thesystem to be by gravitation. v

4In the accompanying illustration I have shown, more or lessIdiagrammatically, certain embodiments of apparatus elements within thepresent invention and suitable for the performance of the stated processv In this showing:

Figure 1 is an end elevation, certain parts being in section, and

Fig. 2 is a side elevation, certain elements being in section.

In this apparatus as shown, three steam stills, A, B and C, are shownmounted in superimposed arrangement. As shown, the still having thelowest temperature, A, is uppermost, while that having the highesttemperature, C, is lowermost, so that the liquid may flow downwardthrough the system by gravitation. As shown, these stills are mounted ona steel framework 1, provided with suitable cradles 2, supportingmembers 3, etc. The necessary heat insulation for the stills isprovided, in the type of still shown, by an upper outer layer 4 ofradial tile or other suitable material supported on angle irons 5. Inthe interior, at the bottom portion of the still, may be another layerof heat insulating material 6. This arrangement is convenient for anumber of reasons.

As shown each still is provided with its own dephlegmating column andthese dephlegmating columns for structural reasons are made onecontinuous structure; the three sections being mounted in superimposedrelation as one continuous column. From still A vapors are led outwardthrough vapor line 7 entering at the base of section 8. As shown thiscolumn is provided with plates`9 of a usual type. Any other kind offilling and film-forming material or structure may be employed in itslieu. Passing upwardly through the columns past these plates the vaporsgo to vapor outlet 10, whence they are led to any suitable condenser(not shown). Liquid is introduced into the top of the column at 11through heat exchanger 12, and may, as shown, pass in countercurrent toand be warmed by the outgoing vapors which pass outward through vaporoutlet 10 to any suitable condenser (not shown). The incoming liquidpasses downward through the column-seclike and receives vapors from Bthrough vapor line 16. The vapors pass uawardly against downflowingliquid coming rom the previous still A through overfiow line 17. Theliquid after passing through this section and being enriched bycondensed vapors passes into B through feed line 17 From B residualliquid passes through overflow line 18 to the top of the lowermostsection zol , still C.

Within, the stills are generally provided with the usual. steamintroduction means 23 and (see Fig. 2) internal bames 24, 25 and 26adapted to cause a tortuous dow of y"liquid from end to end of thestill. As may be seen by Fig. 2, the liquid to be distilled enters atone end of the still and leaves at the other, flowing past the statedbaies. rI`he vapors from the second section (15 pass to any suitablecondenser (not shownl through vapor outlet 27 and those owermost section(19) through vapor out- From the lowermost or hottest still C thethoroughly exhausted liquid is led to a suitable cooler through outlet29. 'Ihe hot liquid may be led through heat ,interchanger 29 to heat theoil supplied to the system (through 11). Pipes 3l, 32 and 32 connectstills-A, B and'C, respectively, to a riser 30, leading to a pump (notshown). 'Ihis construction permits the oil to be pumped from the stillsfor repairs and like purposes. Connections 33, condensed water from A, Band C, respectively into funnel connections 33', 34e and 35 whichconnect to the sewer line 36. Ihe

connections allow the operator to determinevwhen the water has been`drawn entirely from the still.

In the use of the described` structure, crude naphthais allowed to Howin through inlet 11 and is warmed in heat interchangers 29 and 12. Itflows downwardly over the plates 9 until it reaches still A through 14.

In so passing it gives up vapors of low boilmg materials to the vaporsfrom 7 and itself condenses higher boiling lportions of such vapors sothat the distillate obtained by condensing the vapors from 10 is auniform gasolene of good quality. In still A the incoming liquid isdelivered at one end of the still and passes slowly toward the other endpast the baflies and is thoroughly freed' of its low boilingconstituents in so passing., At the time it reaches line 17, it has beenthoroughlyfreed of the grade of naphtha called gasolene. From 17 itflows down through section 15 against the upwardly passing vapors from Band dephlegmates these vapors in a similar way until it reaches still Bthrough line 17. I-Iere it passes from end to end of the still in asimilar manner until it flows outwardly at 18. In so flowing, the secondcomponent of the crude naphtha, which may be here called naphtha,furnishes vapors which in going through section 15 are thoroughlydephlegmated giving a `uniform cut in the condenser (not shown). Theoutiowing liquid from B through 21 into ii vapors from C passing fromthe `method I have 34 and 35 allow draining od'. b

passed in contact passing through 18 into the lowermost section 19,flows downwardly therethrough against the vapors passing from C and itnally reaches C through` inlet 21. The through 20 and 19 at 28 arecondensed to form benzin. flowing through still C the liquid to exitwithdrawn at 29 and cooled in any suitabledevice (not shown) is an oilwhich is equivalent to or is a high grade kerosene distillate.

'Ihe treatment of crude naphtha in the manner just described is oneexemplication of myk invention which may be applied to other distillatesand oils Ithan such crude naphtha; and I may in treating crude naphthause only two stills or more than three stills, the number shown. Iregard my invention as being applicable to cases where it is desired totillates in order uniform cuts or fractions with a uniform u ndistilledhigh boiling residual oil or fraction.

It will be obvious that with the present devised a way of distillation1n which with struction, I can separate a given amount of crude naphthainto gasolene, naphtha and enzin with a comparatively small amount ofsteam, and with a saving of time. The

steam-distil petroleum dis-4 to obtain a plurality ofV a comparativelycheap' conseveral distilled products obtained are of uniform quality anddo not need redistillation. In one operation, I am obtaining gasolene,naphtha and benzin with closer boiling points. There is also a saving inthe amount of condenser water necessaryand a saving in the amount ofground space required.

What I claim is l. 'Ihe process of continuously redis'tilling petroleumproducts which comprises passing a continuous current of a petroleum oilto be distilled through a plurality of successive stills, each such'still being provided with a vapor outlet and dephlegmating column, andthe liquid supplied to each such still first passing through suchdephlegmating column, and the liquid in each such still being caused toflow from end to end thereof in a' more or less tortuous passage for thepurpose of complete exhaustion therein.

2. rIhe process of continuously redistilling crude naphtha for thepurpose of making definite cuts or fractions therefrom which comprisescontinuously supplying such crude naphthato and through a plurality ofstills in series, the oil feeding each such still being with the vaporsfrom such still prior to entering the still and the oil in the stillbeing end of such still passage.

3. rIhe process of continuously distilling petroleum products whichcomprises passing a continuous current of petroleum oil to be in a moreorless tortuous caused to How from end to' distilled through a pluralityof successive stills, the vapors Vfrom one still being conducted pastand contacted with the oi from another still outside of said stills andthe said oil being delivered from said outside source to the still thevapors from which it has passed.

a. The process of continuously distilling petroleum products whichcomprises establishing and maintaining a plurality of stills operatingin series, passing the oil from one still outside of said still and incountercurrent to the vapors from another still, and then passing saidoil into said second still.

5. ln a petroleum still, the combination of a plurality of steam heatedstills arranged in series for the iow of liquid therethrough, each suchstill being provided with a dephlegmating column with the feed of liquidto each still through such dephlegmating column, the liquid flowing1from each preceding still passing through t e dephlegmating column ofthe next succeeding still, and each such still being provided with meansfor causing a flow of liquid in a tortuous path from end to end of thestill.

6. ln a petroleum still, the combination of a plurality of steam heatedstills arranged in series'for the ioW of liquid therethrough, each suchstill being provided with a dephlegmating column with the feed of liquidto each still through such dephlegmating column, the liquid flowing fromeach preceding still passing through the dephlegmating column of thenext succeeding still, each such still being provided 'with means forcausing a. iow of liquid in a tortuous path from end to end of thestill, and such plurality of stills being mounted in verticalarrangement so that the flow of liquid from still to still may bedownward through the serles.

7. In a. petroleum still the combination of a plurality of heated stillsarranged in series for the flow of oil therethrough, each stillbeingprovided with means for delivering vapor therefrom and returningcondensed liquid thereto and a dephlegmating column for each still, andconnections arranged for delivering oil from one still to a succeedingstill in the series past the vapors rising from such succeeding still.

8. In a petroleum still the combination of a plurality of heated stillsarranged in series for the flow of oil therethrough, each still beingprovided with-means for delivering vapor therefrom and returningcondensed liquid thereto, and connections arranged for delivering oilfrom one still to a succeeding still in the series past the vaporsrising from such succeeding still, and means for separately withdrawingand collecting the vapors from each still after such vapors have beencontacted with the oil being delivered by the preceding still.

In testimony whereof, I aliix my signature hereto.

GEORGE L. PRCHARD.

Witnesses:

J. G. GLASGOW, HERBERT HENDERSON.

